So I updated my mods list, adding a bunch of stuff out of the OpenMW STEP guide, and a few other things. I tried to update the load order to be good -- but apparently I failed at this, as I get a LOT of errors and some missing meshes after loading a save file. Pasting links to each file below. I'm trying to take it one at a time, but I'm having problems finding anything on the internet that directly references each issue.

I would advise that you remove the groundcover mods, unless they have been remade for OpenMW. They were never meant to be used in game, but for use in Distant Land Generation for MGE. Unless they are the modified ones, they will impede progress, and whether or not they are modified for OpenMW, they're likely to create quite a performance drain -- They are not set up using the correct structure for ESP files in reality, hence all the warnings.

Okay, let's put that aside for now. I've commented out most of the mesh and flora mods for the time being to focus on other things.

1) Not sure why this is happening -- but may not be a concern.
Loading content file LGNPC_SecretMasters_v1_30.esp
Warning: Failed to insert info 13718315671039429305
Warning: Failed to insert info 185024382359814056

2) Unhandled controller NiPathController on node (various) in meshes/f/photodragons.nif -- also appears to only be a warning.

3) Warning: out of bounds UV set 2 on TriShape "Tri kaguti 0:1" in meshes/r/xleastkagouti.nif (various shapes/sets/files -- I'm guessing this is ALL bump-mapped stuff)

5) Failed to open image: Resource 'textures/tr_tx_cookie_chunks.dds' not found (related to Tamriel Rebuild, I think?)

6) error MU_GH_BC_ShelfFun_HF line 44, column 9 (setx)
Unexpected name
--I'm guessing this has to do with a Graphic Herbalism mod when I have the mod it requires removed. There's many variants of this.

4) Official Add-ons Patched:
Unhandled controller NiPathController on node 2 in meshes/f/photodragons.nif (various nodes mentioned -- other mods which use this file and will eventually overwrite this: Creatures XI, Vibrant Morrowind 4, Better Sounds) -- This is NOT an issue with Official Add-ons patched, it's an issue with how OpenMW handles photodragons.nif, and happens in Bitter Coast Sounds as well.

5) Better Picks and Probes: Uses bump-mapping, leading to warnings re: Out of bounds UV set 2 on TriShape "" in meshes/m/probe_apprentice_01.nif -- presume it's on all the meshes here.